1. Field of the Invention
The present invention relates to a semiconductor device, and particularly relates to a semiconductor device which performs wireless communication by using electromagnetic waves.
2. Description of the Related Art
In recent years, an individual identification technology using electromagnetic waves for wireless communication has attracted attention. In particular, as a semiconductor device which communicates data by wireless communication, an individual identification technology using a semiconductor device (also referred to as an RFID tag, an IC (integrated circuit) tag, an IC chip, an RF tag, a wireless tag, or an electronic tag) utilizing RFID (radio frequency identification) has attracted attention. The individual identification technology using such a semiconductor device utilizing RFID has been useful for production, management, or the like of an individual object, and application to personal authentication has been promoted. Further, recently, a tag which reads and writes data by using a plurality of frequencies has been proposed (for example, Patent Document 1: Japanese Published Patent Application No. 2005-252853).
Such a semiconductor device includes an antenna and an integrated circuit portion which has a signal processing circuit provided with a memory circuit or the like. In general, a plurality of chips each including an integrated circuit portion which is included in a semiconductor device are manufactured from one silicon substrate, and the chips are finely formed so that cost reduction is achieved. For example, Patent Document 2: Japanese Published Patent Application No. 2004-78991 discloses that it is advantageous to manufacture a plurality of chips each under 0.5 mm on a side over a silicon wafer, economically and in terms of the yield.